Plastics are widely used as packaging materials, insulators, components in various machines and devices, and as coating agents. Unfortunately, their widespread use has led to increasing environmental concerns as they are now frequently found in the environment.  Recycling offers a potential solution—but not all chemical recycling methods are equally environmentally friendly. The following provides an overview of chemical processes used to recover value from plastic waste.

Type and Composition of Plastic Waste

The choice of recycling method depends on the physical characteristics of the material and the degree of contamination or  interaction with other substances. Plastics fall into three main categories: thermoplastics, thermosets, and elastomers. Thermoplastics, such as PVC, polyethylene, and polypropylene, soften when heated and can be reshaped and reused once cooled.

These materials can only be recycled by chemically breaking down the molecular bonds in their polymer chains. This process known as solvolysis. Elastomers, which behave like rubber, also decompose at high temperatures. However, they can still be recycled in shredded form, for example, as filler in bitumen applications.

The degree of mixing significantly affects the recycling process. Homogeneous plastic waste is easiest to recycle. When different types of plastics are mixed, combined with other materials, or contaminated, extensive sorting and separation steps are often necessary—especially in the case of collected packaging waste, composites, and coated components. Surface coatings, commonly used to enhance the performance of plastic parts, often interfere with recycling and must be removed in advance.

Types of Recovery Processes

There are three main categories of recovery for plastics within sustainable chemical practices: mechanical recycling, chemical (feedstock) recycling, and energy recovery.

• Mechanical recycling preserves the base material. The plastic is cleaned and reprocessed—using dry, wet, or solvent-based techniques—so that it can be reused. These methods are primarily physical and mechanical.
• Chemical recycling (also called feedstock recycling) uses chemical reactions to break down plastics into raw materials, which can then be used to make new products.
• Energy recovery is not considered a recycling method in the strict sense of chemistry. In this process, plastic waste is incinerated to generate energy.

Chemical Recycling Methods

The most common chemical recycling methods are liquefaction (oil recovery), solvolysis, gasification, and pyrolysis. These often require pre-treatment steps to remove contaminants, such as separating multi-layer materials (e.g., beverage cartons, coated films) or stripping surface coatings. Eco-friendly paint stripping agents are available for these tasks.

Liquefaction (Oil Recovery)

In this process, plastics are converted into oily substances through thermal or catalytic reactions, which requires well-sorted plastic waste. The reaction typically occurs in stirred tank reactors at temperatures up to 750°F (400°C). As the plastic liquefies, gaseous by-products and wax-like residues are separated from the resulting oil.

After purification and distillation, the recovered oil can be used as diesel fuel or as a chemical feedstock.

Solvolysis

Solvolysis breaks down the polymer chains in plastics using special solvents. The reaction may be aided by elevated temperatures and is primarily used for recycling thermosets. It yields the original building blocks of the plastic, which are then separated from the solvent.

The solvents are usually reused in a closed-loop system. Depending on the input material, valuable raw components can be recovered from the decomposed polymers.

Gasification

Gasification is conducted at temperatures of up to 2,900°F (1,600°C) and pressures up to 2,175 psi (150 bar) with limited oxygen supply. This oxygen does not support combustion but facilitates the reaction between carbon and oxygen. The process produces a synthetic gas (syngas) composed of carbon monoxide and hydrogen. Before further use, impurities must be removed. Syngas serves as a raw material for a wide range of chemical products, including GTL (gas-to-liquid) oil, which is used in surface treatment applications.

Pyrolysis

Pyrolysis involves the thermal decomposition of plastic waste in the absence of oxygen at temperatures between 300–1,300°F (150–700°C). One of the oldest known pyrolysis methods is the production of charcoal in kilns. Modern pyrolysis of plastics yields solid, liquid, and gaseous products, which can be processed into valuable chemical precursors.

Comparing Recycling Methods

Chemical plastic recycling requires a high amount of energy as well as extensive pre- and post-treatment steps involving additional auxiliary substances. For this reason, material recycling—which reuses materials without chemical changes—is given priority. When this is not feasible, energy recovery is often the more sustainable option. Under certain conditions, however, chemical recycling methods can still be advantageous. They allow harmful substances to be removed from the material cycle and can supply the chemical industry with valuable raw materials.

This is especially true when larger quantities of homogeneous plastic waste from one or similarly composed materials are available. Research is actively working to improve plastic recycling methods, gradually making this form of plastic recovery more prominent in the future.

Regulatory Considerations

This is particularly true when large quantities of homogeneous plastic waste are available from a single or similar source. In the United States, recycling operations must comply with EPA regulations under the Resource Conservation and Recovery Act (RCRA), which governs how facilities manage hazardous and non-hazardous solid waste. Ongoing research is actively improving chemical recycling methods, making them an increasingly viable part of future waste management strategies.

Der Beitrag Plastic Recycling in Chemistry erschien zuerst auf Kluthe Magazine.

EcoVadis SAS is a Paris-based company, established in 2007, that operates globally to assess sustainability practices within companies. The outcome is the EcoVadis Sustainability Rating. This rating allows participating companies to precisely determine their standing compared to others in their industry and identify areas for improvement. Learn here about how the service works and what the EcoVadis Rating truly entails.

Why EcoVadis Rating?

Many companies strive to improve sustainability for various reasons. For example, the chemical industry is interested in demonstrating to society how it increasingly minimizes the environmental impact of production through green chemistry, achieves social goals, and makes supply chains for raw materials in the chemical sector progressively more sustainable. A challenge in this area is defining measurable goals and indicators to track improvements and make comparisons. EcoVadis helps companies overcome these challenges by providing a reliable assessment and monitoring of their sustainability performance.

Questions that might influence the assessment include:

• Has the company calculated a CO2 balance?
• Does it set CO2 reduction targets?
• How does it  manage finite and critical resources?
• Is there a human rights officer?
• Is there a sustainable waste management and recycling program?
• How are gender equality and occupational safety ensured?
• Are there comprehensive employee training programs?
• Is the supply chain traceable?
• Does the company engage in social initiatives?

Service Management

To monitor a company’s sustainability and rate it through EcoVadis, reliable information on operational standards, treatment of employees, respect for human rights, and environmental protection along the supply chain is needed. The company uses diverse information sources, including client documents, third-party certificates, business partner data, and publicly available information. This data is stored in a secure cloud and protected from loss and unauthorized access, through processing via a SaaS platform. SaaS stands for Software-as-a-Service, a model widely used in customer relationship management (CRM) where it supports process optimization and profitability enhancement. A unique, specially developed methodology is available for sustainability assessment. This methodology enables a comprehensive rating of a company’s commitment to sustainable practices (Corporate Social Responsibility, CSR).

Methodology for EcoVadis Rating and Scorecard Creation

Alongside the EcoVadis Rating, which allows companies to compare their sustainability management with others in the same industry, EcoVadis creates a scorecard. This report details individual results and highlights areas for improvement. Built on international sustainability standards like the United Nations Global Compact, the Global Reporting Initiative, and ISO 26000, the EcoVadis methodology is based on seven core principles:

1. Assessments are conducted by highly qualified international experts.
2. Evaluation procedures are tailored to specific industries, company sizes, and countries.
3. Using all available sources ensures extensive stakeholder input for a reliable rating.
4. Modern Technology enables secure, confidential processes with accelerated processing times.
5. Documentation is transparent and traceable.
6. Evaluation is based on empirically derived and scientifically validated information.
7. Continuous improvement in assessment processes enhances methodological excellence.

The EcoVadis Sustainability Scorecard

The EcoVadis Sustainability Scorecard contains the assessment results, covering four areas that are also relevant to the chemical industry and promote sustainable chemistry:

• Environment
• Labor and human rights
• Ethics
• Sustainable procurement

Twenty-one indicators are available for evaluating individual performance. These indicators generate points that contribute to the company’s overall rating, allowing for easy comparison of sustainability performance across companies. Additionally, the point scores are used for the rating, which is linked to the awarding of recognition medals: Platinum (top 1%), Gold (top 5%), Silver (top 25%), and Bronze (top 50%). These medals can be used in corporate materials for promotional purposes.

Using the Scorecard in Business Relationships

The EcoVadis Scorecard can be requested by other companies to assess if a business partner meets high standards or presents CSR risks, impacting supplier selection. Clients may also require corrective measures from suppliers if needed. For instance, the chemical industry can only truly engage in green chemistry if raw material suppliers practice sustainable chemistry. A supplier’s scorecard provides reliable insight into the standards of its production processes.

Summary of the EcoVadis Rating Benefits

An established methodology with proven technology, quickly delivers a comprehensive assessment of a company’s sustainability, meeting environmental, sustainability, and legal requirements. Self-assessment questionnaires are tailored to company needs, while strengths and improvement areas are revealed through the EcoVadis Rating. Key performance indicators facilitate efficient, trackable improvements, and the scorecard information exchange between companies strengthens business networking.
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Der Beitrag What Does the EcoVadis Rating Indicate? erschien zuerst auf Kluthe Magazine.

In the 1990s, the concept of the “sustainability triangle” gained traction in environmental discussions.  It was particularly influential in the chemical industry, which contributed valuable insights—arguing that sustainability must encompass not only ecological concerns but also economic and social aspects. This perspective sparked widespread interest across other industrial sectors. Here is a look at what the sustainability triangle entails and how this model has influenced climate protection efforts.

What Is the Sustainability Triangle?

The sustainability triangle is a conceptual model based on the interconnectedness of natural and societal processes. Most human actions can be categorized into three spheres: ecology, economy, and society. The triangle serves as a visual metaphor for these relationships.

A  closely related model is called the “three pillars of sustainability,” where each pillar represents one of the three core areas. Both concepts are widely used in politics and business to develop strategies for a sustainable and equitable world that benefits everyone. Such a world becomes possible when balance is achieved between environmental health, economic activity, and social cohesion.

Ecology in the Sustainability Triangle

A healthy environment is the foundation of all human life. This includes the physical and chemical conditions essential to our metabolism—such as temperature, air pressure, and the absence of toxins—as well as basic elements like air, water, and food.

Over millions of years, a stable natural balance allowed life, and eventually humanity, to emerge. This balance depends on a web of natural cycles—evaporation and precipitation, food chains, respiration and photosynthesis.

Industrial development, however, has led to a growing disconnect from nature. While this progress has brought prosperity to many, it has also come at the cost of environmental exploitation. For years these negative impacts were largely overlooked. Now, we face an ecological imbalance that threatens our very foundation for life. Ecology, therefore, plays a crucial role in the sustainability triangle. Its main objectives include:

• Climate protection to safeguard the physical conditions for life
• Habitat preservation to maintain biodiversity
• Pollution prevention across air, water, and soil
• Responsible use of natural resources, such as raw materials, water, and land

A return to a purely “natural lifestyle” is neither realistic nor desirable. Instead, society—and especially industry—must  develop innovative solutions to meet ecological challenges in  the modern world.

The Role of the Economy in the Sustainability Triangle

People rely on essentials like food, clothing, housing, and tools. Providing this is the task of the economy, especially industries, agriculture, and commerce. The financial sector ensures that these  domains remain operational.

A sustainable economy requires responsible business practices that support environmentally sound production. As global supply chains expand, this responsibility must also extend to the sourcing of raw materials.

A sustainable economic model relies on technologies that align with environmental goals, such as:

• Energy from renewable sources
• Efficient use of energy and raw materials
• Durable products
• Waste recycling
• Product refurbishing and reuse
• Emission reduction

The chemical industry plays a key role in developing these technologies. Fundamental research in chemistry lays the groundwork for practical applications. Applied chemistry then creates eco-friendly products. Two  primary areas of focus are sustainable chemistry and green chemistry, with the latter focusing on the environmentally sound production of raw and consumer materials.

For example, the use of sustainable products for surface treatment is steadily increasing. . And sustainable chemistry ensures that even downstream users of these materials can act in an environmentally conscious way.

The Social Dimension of the Sustainability Triangle

The sustainability triangle also recognizes  that individuals must be empowered to take part in environmental protection. But that requires having the freedom to choose. People struggling to meet basic needs cannot be expected to maintain the world for the privileged.

This is particularly relevant for populations in developing countries. A key step is giving them access to modern, eco-friendly technologies. Equally important is fair trade, which provides people with an income sufficient to support a dignified life for themselves and their families. In the United States, the EPA’s Environmental Justice initiatives focus on this social dimension through programs like the Environmental Justice Small Grants Program and EJSCREEN mapping tool, which help identify communities disproportionately affected by pollution and environmental degradation.

When poverty is reduced globally, it creates better conditions for addressing other social goals—such as adequate food and drinking water, healthcare, education, and cultural participation.

Connecting Ecology, Economy, and Social Responsibility

By definition, the sustainability triangle is equilateral, meaning each side holds equal importance.  Likewise, the three pillars of sustainability are of equal length. Industry and finance recognize that ecology, economy, and social concerns are equally vital for sustainable development. The idea is to create a world that is viable, livable, and fair:

• Ecology + economy = a viable foundation
• Economy + social responsibility = fairness
• Ecology + social responsibility = livability

That logic seems sound, but even flawless logic only shows us the correct path of reasoning. Whether the conclusions match reality depends on whether the initial assumptions are true. If they are incomplete or flawed, even perfect logic will not lead to the right answers. That is when real-world experience becomes essential.

Each goal within the sustainability triangle is worth striving for. But not all goals are equal in priority. Some are prerequisites for others.

Many environmental scientists and policy experts argue that climate protection should be a leading priority. Different stakeholders, however, may rank these priorities differently based on their values and contexts. The theoretical model of equal weighting has been criticized by some for potentially slowing progress on urgent environmental issues. Ecology, economy, and social factors must form a unified approach in industry—with the balance being determined by  both scientific understanding and societal values.

In the United States, this approach aligns with evolving regulatory frameworks from the EPA and state environmental agencies, as well as voluntary corporate sustainability standards like those promoted by the Sustainability Accounting Standards Board (SASB). Companies increasingly recognize that proactive sustainability measures can help them stay ahead of regulatory requirements while building consumer trust.

A balance still exists if the unity of economy and social needs counterbalances ecological demands. But an ecologically healthy environmentis the precondition for life itself.  For true sustainability, the economy must operate within ecological limits  so that broader social goals can be achieved.

Der Beitrag The Sustainability Triangle erschien zuerst auf Kluthe Magazine.

How Can CO2 Be Captured?

Carbon dioxide binding can be achieved through both biological and technical methods.

Biological Methods

Biological carbon binding relies on photosynthesis, the basis of plant growth. However, CO2 captured by plants is often re-released into the atmosphere through natural decomposition. Thus, plants can only serve as long-term carbon storage if additional steps are taken to prevent biomass breakdown.

Technical Methods

Technical methods for carbon dioxide binding are closely linked to the capture of CO2 from the atmosphere or industrial emissions. Permanent carbon dioxide binding is then achieved through utilization or storage. The following terms and abbreviations have become standard for these processes:

• Direct air capture of CO2 (DACC)
• Carbon capture and utilization (CCU)
• Carbon capture and storage (CCS)

Plant-Based CO2 Binding Methods

How Much CO2 Does a Tree Capture?

Trees primarily bind CO2 in the wood of their trunks, branches, and roots. The amount stored depends on factors like tree species, growth conditions, and development stage, which influence the amount of wood produced. About half of the dry wood’s mass is carbon; by multiplying this value by 3.67, we can estimate the mass of carbon dioxide the tree has absorbed from the air.

For those who want to calculate: 12 g carbon + 2*16 g oxygen = 44 g CO2; 44 : 12 = 3.67.

You can find the atomic masses in the periodic table of elements.

A more informative metric is the amount of greenhouse gas that can be captured through reforestation. A general rule of thumb is that forests can sequester about six metric tons (or approximately 13,200 pounds) per 2.5 acres each year. However, this applies only to forests with healthy trees of all developmental stages growing under favorable climatic conditions. Water is also required for wood formation, so in the absence of rain, growth is delayed. Sustainable forest management and reforestation is necessary to replace what has been used in commercial industries such as; construction, furniture production and in other consumer goods, for long-term CO2 binding in forests.

CO2 Binding in Biomass

There are several effective ways for biomass—such as crops, plant residues, or algae—to bind CO2:

• Peatland restoration: where peat forms in oxygen-free conditions from biomass and remains in the soil as a carbon dioxide sink.
• Biochar production: by heating under oxygen-free conditions (similar to charcoal production), which can be used as a raw material in the chemical industry or for soil improvement in agriculture.
• Humus formation as a soil carbon sink
• Production of chemicals from biomass
• Combustion of dried biomass for energy generation, with CO2 capture and storage or utilization from flue gases
• Production of biofuels to reduce emissions from fossil fuel sources

Technical Methods for CO2 Binding

Direct Air Capture

Direct capture is very costly due to the relatively low concentration of CO2 in the air. Large fans with high air throughput are required to achieve significant yields. Several methods are available for capture:

• Gas scrubbing with liquid organic amines or caustic soda
• CO2 binding through adsorption onto a solid (sorption)
• Binding by anion exchangers with polymer resin
• Membrane technology to separate carbon dioxide from air.

The economic feasibility of these methods depends on the extent to which captured CO2 can be used. Factoring in the damage caused by global warming could shift the economic calculation significantly in favor of carbon dioxide capture.

Capture from Combustion and Industrial Emissions

With a higher concentration of CO2, capturing emissions from combustion gases is more cost-effective than air capture. Gas scrubbing with liquid organic amines is the preferred method here. Additionally, significant amounts of CO2 are produced in industries like cement production, metallurgy, and other chemical processes, which can be captured, separated, and utilized for long-term binding,  much like CO2 captured from the air.

Sustainable Binding: CO2 Utilization Options

Production of Chemicals and Fuels

CO2 can be catalytically converted into basic chemicals and further processed. Examples of raw materials include urea and methanol. End products might include plastics or synthetic lubricants that serve as  storage. Additionally,  it is possible to produce fuels and energy sources. Although this does not reduce CO2 levels in the air—since burning the materials releases CO2 again—it reduces emissions through a circular economy approach.

Enhanced Weathering

CO2 can be catalytically converted into basic chemicals and further processed. Examples of raw materials include urea and methanol. End products might include plastics or synthetic lubricants that serve as CO2 storage. Additionally,  it is possible to produce fuels and energy sources. Although this does not reduce CO2 levels in the air—since burning the materials releases CO2 again—it reduces emissions through a circular economy approach.

CO2 Binding in Concrete Building Materials

Concrete materials contain calcium hydroxide in their pores, which reacts with atmospheric CO2 to form calcium carbonate, strengthening the concrete. This natural aging process enables concrete to function as a carbon dioxide sink. During concrete recycling from demolished buildings, this process can be exploited by exposing crushed concrete to CO2 compacts the structure and reduces pore volume.

Der Beitrag Overview of CO2 Binding Options erschien zuerst auf Kluthe Magazine.

What Do Greenhouses and  Earth’s Climate Have in Common?

In a greenhouse, electromagnetic radiation from the sun passes through the transparent walls and roofs, mostly as visible light. When this radiation hits interior surfaces, they absorb it and heat up.

The heat becomes trapped, raising the temperature of the air and objects inside the greenhouse. Greenhouse gases function similarly. They allow shortwave solar radiation to pass through but partially absorb or reflect the longwave thermal radiation emitted by the Earth’s surface.

© Siberian Art – stock.adobe.comThis distinguishes them from the main components of air, namely nitrogen and oxygen, which let both short and long waves pass through almost without obstruction. The reason lies in molecular structure: Heat is the motion of atoms within a substance. Nitrogen and oxygen molecules consist of only two atoms and can only vibrate in limited ways. Greenhouse gases, by contrast, have three or more atoms and can vibrate in more complex patterns, which allows them to absorb or reflect a wider range of wavelengths and thus trap more heat.

Why Are Greenhouse Gases Harmful?

The most important greenhouse gases are water vapor and carbon dioxide. Both have existed in Earth’s atmosphere long before industrialization. Water vapor enters the atmosphere via evaporation and remains there until it condenses into clouds and returns to the ground as rain, snow, or hail.

Industrialization, transportation, and intensive agriculture have disrupted this balance. Over the past 200 years, human activity has significantly increased carbon dioxide concentrations and introduced other greenhouse gases into the atmosphere. The result has been rising temperatures.  The warmer air holds more moisture, and a thawing permafrost releases even more gases.

This creates a feedback loop that intensifies the greenhouse effect. The consequences include extreme weather events, melting ice masses, and infrastructure damage, which in turn impact supply chains for raw materials and energy. Rivers and lakes dry up during droughts, affecting industries such as chemicals and energy that  depend on water for cooling. When water levels drop and temperatures rise, discharging wastewater into rivers becomes unsustainable. In some cases, discharge bans must be issued to protect ecosystems—bringing chemical production to a standstill. In short: Emitting greenhouse gases, in the chemical industry and beyond, is ultimately self-destructive.

What Greenhouse Gases Exist?

In addition to water vapor and carbon dioxide, other major contributors to the greenhouse effect include methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF₆), and nitrogen trifluoride (NF₃). HFCs and PFCs belong to the group known as fluorinated gases (F-gases). In the United States, emissions of these substances from building operations, transportation, agriculture, and industry are measured and reported annually through the Environmental Protection Agency’s Greenhouse Gas Reporting Program. This monitoring ensures transparency and helps shape both domestic climate policy and international commitments. Other climate-relevant substances include ground-level ozone, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ammonia (NH₃).

Thanks to progress in chemistry, emissions of many of these substances have steadily decreased across all sectors. However, their climate impact varies depending on how much thermal radiation they can absorb or reflect—and how long they remain in the atmosphere. This is  measured the Global Warming Potential (GWP), which quantifies the warming effect of a substance over 100 years relative to carbon dioxide.

The GWP values (in CO₂ equivalents) are as follows:

• Carbon dioxide (CO₂): 1
• Methane (CH₄): 25
• Nitrous oxide (N₂O): 298
• Nitrogen trifluoride (NF₃): 17,200
• Sulfur hexafluoride (SF₆): 22,800

Where Are Greenhouse Gases Generated?

Carbon Dioxide

CO₂ emissions make up the largest share of all greenhouse gases. They are primarily released during energy generation from fossil fuels and fuel combustion in vehicle engines. The chemical industry is particularly energy-intensive. A significant share of its greenhouse gas emissions results from electricity use and from generating steam and hot water for heating. Additionally, many chemical processes release CO₂—for example, the production of soda ash, ammonia, and cement. Other large industrial sources include steelmaking and building operations.

Methane

Methane forms when organic matter is broken down by microorganisms in the absence of oxygen. Major sources include agriculture, sewage treatment plants, and landfills.

Nitrous Oxide

Nitrous oxide, also known as dinitrogen monoxide (N₂O), is produced when nitrogen-based compounds break down in soil—especially synthetic fertilizers and manure. That makes agriculture, particularly factory farming, a key contributor. In the chemical industry, large quantities of N₂O are released during the production of caprolactam, adipic acid, and nitric acid. Caprolactam and adipic acid are used to make plastics; nitric acid is a basic chemical feedstock in many applications.

Fluorinated Hydrocarbons (F-Gases)

F-gases are synthetic chemicals used primarily as propellants, refrigerants in air conditioning systems, and fire suppression agents. Their use is regulated by two specific F-gas regulations. To minimize emissions, systems are subject to regular leak inspections and must be properly decommissioned. Reclaiming refrigerants from scrapped equipment also helps reduce emissions.

Sulfur Hexafluoride (SF₆)

SF₆ is a very dense, inert gas used as an insulator in electrical systems. It is also used in soundproofing  windows and in semiconductor manufacturing. Emissions can be minimized by using sealed, hermetic systems.

Nitrogen Trifluoride (NF₃)

NF₃ is widely used in semiconductor manufacturing. It serves as a cleaning gas for solar panel production and liquid crystal displays (LCDs). Emissions can be reduced by using fully enclosed systems.

Der Beitrag What Are the Main Greenhouse Gases—and Which Ones Are Especially Relevant in the Chemical Industry? erschien zuerst auf Kluthe Magazine.

Global raw material reserves are finite. Humanity consumes more resources than nature can regenerate. At the same time, so much waste is generated that the environment is overwhelmed by the burden. This situation calls for action: recycling conserves resources and reduces environmental impact. If the foundations of life on Earth are to be preserved, recycling must be pursued much more intensively in the future. What types of recycling are there? What contribution can the chemical industry make to recovering valuable materials? Here is what you need to know.

Capabilities and Limits of Recycling

Recovering valuable materials from waste requires a certain amount of energy and, in many cases, processing chemicals. The scale of this effort depends primarily on how many different materials the waste contains and how strongly these are bonded or intermixed.

The chemical industry can provide and develop processes that enable material separation and the transformation of processed substances back into raw materials. Whether the required effort is justified and to what extent sustainable chemistry can be applied, depends on the specific properties of the waste. That is why more effective recycling will only be possible if recyclability is built into product design and manufacturing.

It is also necessary to harmonize the design of components that serve the same function so that they are interchangeable. This has long been the case with screw threads and electrical connectors. A tentative step in this direction is the unification of charging cable connections for cell phones.

Future Recycling: An Overview of Key Types

In the future, three distinct types of recycling will continue to be utilized:

• Material recycling (recovery of raw materials)
• Production waste recycling (direct recycling of industrial waste)
• Product recycling (reuse of materials and components)

Prevention of waste generation always takes precedence over recycling. Since this principle cannot be fully realized in the future, recovery and reuse in industry will become increasingly important. The recycling methods used should require as few process steps as possible, consume little energy, and make use of sustainable chemistry.

Material Recycling

The chemical industry is particularly important for material recycling in the future. If an object or its individual parts can no longer be used, at least the materials they contain should be returned to the economy. Material recycling begins with dismantling products into their components and separating the materials. Through further processing steps that ideally meet the principles of green chemistry, the materials can once again be made available to industry as raw materials.

Material Recycling of Metal, Glass, and Paper

Metals are the easiest to sort and recycle. Different physical properties such as electrical conductivity, density, solubility, or melting point make it possible to automate this process—at least in part. The recovered metals are melted down and cast into new products or semi-finished goods. Metallurgy has used this type of recycling throughout history. The recycling of wastepaper and glass has a similar history. For glass and paper recycling, the chemical industry has developed processes that consume less water, energy, and processing chemicals than producing these materials from virgin raw materials. These methods will also maintain their importance for recycling in the future.

Material Recycling of Plastics

Material recycling is more difficult with plastics. Their closely related physical properties make it harder to separate materials. That is why collecting recyclable materials separately is especially important here. For mixed plastic waste, the chemical industry has different processes (pyrolysis, liquefaction, gasification) that break the material down into its basic building blocks and make them usable again as raw materials. However, these processes require so much energy that energy recovery is still more economical at present. If the chemical industry succeeds in further improving these methods, material recycling of plastics will gain importance in the future.

Production Waste Recycling

In manufacturing, material waste and sometimes defective goods are generated on a regular basis—including in surface treatment. In these cases, composition and properties are well known, and contamination is minimal. As a result, recycling in industry is relatively straightforward. The best-known example is the return of chips and scrap from metalworking into the economy. Collected by type, this waste also generates a worthwhile return.

In the chemical industry, most waste consists of used process chemicals. These can be broken down into their components by various separation processes. Many chemical companies operate facilities in which they reprocess residual materials from their customers. For this purpose, Kluthe founded the subsidiary Rematec. Rematec has developed specialized patented processes that use green chemistry for processing waste from the chemical industry.

Product Recycling

Product recycling preserves either materials or complete components. In this area, reuse and repurposing takes place. Reuse means employing a part again after an overhaul. Repaired and cleaned, the components resume their original function. This is the case, for example, with reusable deposit bottles. Frequently, old car parts also get a second life in this way. Repurposing uses materials for a new purpose. A well-known example is single-use deposit bottles that are collected by type and processed into granulate. New plastic products can then be manufactured from this.

The prerequisite for product recycling is careful separation of waste. For future recycling, deposit systems will therefore become increasingly common. Current practices such as separating household waste and returning electronics or batteries do not attract enough participation from the public and industry. Corresponding deposit systems would provide stronger motivation in the future.

Sources:
[1] https://ethz.ch/content/dam/ethz/special-interest/mtec/sustainability-and-technology/PDFs/ETH%20Global%20Recycling%20Survey%202020.pdf

Der Beitrag Recycling in the Future erschien zuerst auf Kluthe Magazine.

Barrels are a widely used packaging solution for chemicals consumed throughout the industrial sector. Lubricants, cleaning agents, corrosion protection products, paints, and coatings can be safely stored and transported in them, protected from environmental influences. The large number of deliveries alone represents significant potential for greater climate protection and resource efficiency. Using reconditioned barrels can significantly reduce CO₂ emissions. Read on to discover how this process works and how you can take part.

When Barrels Can Be Reconditioned

Steel and plastic barrels can be reconditioned if certain requirements are met. They must be:

• undamaged
• emptied of residues (free-flowing, drip-free, or scraped clean)
• pretreated if they contained toxic, corrosive, or strong-smelling materials (product-free, neutralized, and odor-free)
• free from product residues on the outside
• tightly sealed
• labeled with information about the last contents
• suitable for proper cleaning

In addition, plastic barrels used for hazardous substances have a maximum service life of five years, since plastic materials age over time. For steel barrels, the wall thickness must still be at least 0.04 inches (1 mm). If all these conditions are met, the reconditioning of barrels containing hazardous materials can be performed by a certified company. Be sure to leave all labels and markings that provide information about the former contents on the barrels. This enables the reconditioner to select the appropriate cleaning method for the interior.

Incidentally, empty steel and plastic barrels that are reused within the chemical industry are considered products. A deformed or otherwise damaged barrel sent for repair or recycling, on the other hand, is classified as waste. Using reconditioned barrels therefore not only contributes to reducing CO₂ emissions but also improves the overall waste balance. To take advantage of this benefit, a formal declaration is required—available as standardized forms—confirming that the container has been emptied and is intended for reconditioning.

How Barrels Are Reconditioned

Reconditioning means preparing barrels for reuse. This distinguishes it from recycling or other forms of recovery. During reconditioning, the barrel remains intact as a transport and packaging unit. In recycling, only the material itself is returned to the production cycle, requiring a corresponding amount of energy. In other recovery methods such as incineration, plastic barrels may generate energy but also release CO₂.

Significant CO₂ reductions are achieved when steel and plastic barrels are simply restored for reuse. Steel barrels receive thorough internal and external cleaning, new gaskets, and if necessary, new closures. The internal cleaning may be thermal or chemical, depending on the last contents. In thermal cleaning, barrels are carefully thermally treated under controlled conditions and then repainted. Chemical cleaning is accomplished by using hot steam or hot water and the necessary cleaning agents.

Plastic barrels are also thoroughly cleaned inside and out; closures and gaskets are replaced. For barrels intended to be used for transporting hazardous goods (identified by the UN marking), additional inspection for integrity and required labeling is performed. Reconditioned barrels for liquids must also undergo a leak-tightness test.

Who Performs Barrel Reconditioning

Most products supplied by the chemical industry in barrels are classified as hazardous materials. During transport, they are classified as dangerous goods. The containers used are subject to type-approval testing—in Germany, this process is carried out by the Federal Institute for Materials Research and Testing (BAM), and in the United States by the Department of Transportation (DOT). When barrels are reconditioned, their approved design must not be altered. The new gaskets and closures used must also comply with the original design.

To ensure this, reconditioners of hazardous-material barrels must operate under a recognized Quality Assurance Program (QSP) that describes their reconditioning procedures. In Germany, this program is approved following an initial audit and annual inspections by BAM and similar certification processes exist in the US under DOT and EPA oversight. Each certified company receives an identification code, which becomes part of the labeling on reconditioned barrels.

The QSP may also specify that cleaning methods follow the principles of sustainable chemistry, including the selection of cleaning techniques, the chemicals used, and the handling of waste residues from reconditioning. Industry-wide return systems for industrial packaging operate in both Germany (under the Packaging Act) and the United States, and are operated by certified barrel reconditioning companies.

Green Chemistry in Reconditioned Barrels at Kluthe

Since sustainable chemistry has been part of Kluthe’s corporate philosophy from the very beginning, the company embraces every opportunity to apply best practices in this field. Consequently, Kluthe also offers its products in reconditioned barrels. The CO₂ savings amount to roughly two-thirds compared with newly produced barrels that are recycled after a single use. Over the course of a year, this adds up to more than 660,000 lbs. (≈ 300,000 kg) of CO₂ saved.

This impressive reduction is achieved by extending the service life of the containers. The need for raw materials, transport, manufacturing energy, and waste disposal associated with producing and discarding single-use barrels is eliminated with the use of reconditioned ones.

In addition to reducing CO₂ emissions, conserving resources such as water and processing materials has further positive environmental effects. This is reflected in the sustainable process by which customers return their empty barrels for reconditioning. Kluthe’s own carbon-neutral logistics service collects empty containers during deliveries of new products, which can often be refilled and reused with the same chemical product after cleaning.

By using reconditioned barrels and returning them for reconditioning, customers also improve their own CO₂ footprint and waste balance—while saving disposal costs.

Der Beitrag Reconditioned Barrels erschien zuerst auf Kluthe Magazine.

Global warming is arguably the greatest threat of our time. Looking at prehistoric periods, we see that during every major climate shift, the species that went extinct were the most highly developed. Avoiding greenhouse gas emissions can slow down or even halt climate change. Classifying emissions into Scope 1, 2, and 3 categories provides an overview of their sources, enables the targeted quantification of emissions within each area, and helps identify measures for reducing them.

Classification of Emission Sources in the Greenhouse Gas Protocol

The classification into Scope 1, 2, and 3 emissions originates from the Greenhouse Gas Protocol (GHG Protocol). It is a standard for measuring and reporting greenhouse gas emissions that considers the entire value chain. The basic idea is that businesses are closely interconnected. The production of goods and the provision of services always involve both suppliers and customers. Economic activity is not possible without this interaction. Greenhouse gases released by any market participant are, in part, the responsibility of all companies that rely on their services or receive payment from them. This principle runs through the entire value chain—from raw material extraction to the use of and final disposal of products.

The Greenhouse Gas Protocol distinguishes between direct and indirect greenhouse-gas releases. Direct releases are gases a company itself sends into the atmosphere and can be measured on site. Indirect releases occur at partners across the value chain. When they stem from purchased electricity, heat, or cooling, their magnitude can be estimated from energy consumption; other indirect GHG output is harder to quantify. Scopes 1, 2, and 3 map to these three areas.

• Scope 1: Direct release of greenhouse gases by the company itself.
• Scope 2: Indirect release from energy providers.
• Scope 3: Indirect release along the upstream and downstream supply chain.

Collecting Emissions Data for Scope 1 and 2 Emissions

Information that can be used to derive emission volumes in these areas is mostly available from accounting and technical systems. Accounting departments track exactly what the company spends money on. Based on invoices for electricity, fuel oil, natural gas, and vehicle fuel, consumption figures can be determined. By multiplying consumption with emission factors, greenhouse gas emissions can be calculated in CO₂ equivalents.

Emission factors are conversion values expressed as CO₂ equivalents per kilowatt-hour, gallon, cubic foot, or unit of production. The last category is relevant for agricultural products such as meat or milk. Extensive lists of emission factors are included in the GHG Protocol. In the United States, the Environmental Protection Agency (EPA) provides emission factors through its AP-42 database and other resources, which are widely used for environmental reporting and regulatory compliance. Direct emissions from the company’s own production processes can be calculated using mass-balance methods based on the chemical reactions involved. Alternatively, modern gas measurement and analysis systems can be used to determine the amounts directly in the exhaust stream.

Direct releases of greenhouse gases resulting from in-house production processes can be calculated using substance and mass balances based on the relevant reaction equations. Alternatively, modern measurement and analysis technology can determine quantities directly in the exhaust stream.

Collecting Emissions Data for Scope 3

To better determine the many types of Scope 3 emissions generated by upstream and downstream activities of other companies, the following 15 categories have been defined.

Upstream Activities

• Purchased goods and services (raw materials, consumables, services)
• Capital goods (production infrastructure)
• Share of fuel and energy use by upstream companies
• Transport and distribution (purchased logistics services)
• Waste generated in operations (packaging, process waste, etc.)
• Business travel (public or rental)
• Employee commuting
• Leased buildings, machinery, etc.

Downstream Activities

• Transport and distribution of sold goods
• Processing of sold products
• Use of products sold by end users
• Disposal or treatment of products sold at end-of-life
• Leased assets (facilities, equipment, or vehicles operated by other firms)
• Franchises
• Investments in external companies or projects

Accounting is also the first source of information for Scope 3. Invoices and receipts show what was purchased or sold and what services were used. Service contracts often specify the exact scope of services rendered.

The R&D department may provide further insight into greenhouse gas emissions in downstream activities, including product usage and end-of-life disposal. It stores technical product data and manuals. Additional emission data from upstream and downstream partners may be available from their climate reports.

Complex supply chains and limited data from partner companies make calculating Scope 3 greenhouse gas emissions challenging. In such cases, general emission factors can be used to estimate values.

Identifying Relevant Emission Sources

Not all emission sources have equal impact on climate protection. The focus should be on sources within the value chain that release the largest amounts of greenhouse gases. These are the most promising leverage points for effective reduction strategies. These can be found in upstream, internal, or downstream activities.

Companies can exert the most direct influence on material consumption and energy efficiency in their own operations. For instance, surface treatment processes often involve high temperatures and special process chemicals. Selecting optimal chemical products and avoiding heat loss improves sustainability and reduces Scope 1 emissions in the surface treatment business.

Sustainable chemistry—also known as green chemistry—supports surface treatment efforts. As an upstream supplier, it can provide tailored products that enable optimal processing for cleaning and coating of workpieces, whether through painting or the use of lubricants. When green chemistry principles are applied, it reduces not only its own greenhouse gas footprint but also contributes to lowering the Scope 1, 2, and 3 emissions of its partners.

Der Beitrag Scope 1, 2, and 3 Emissions erschien zuerst auf Kluthe Magazine.

Sources of Used Oil

The purpose of used oil recycling is to recover base oils from waste mineral-based fluids. Beyond their role as fuels and heating oils, they are mainly applied for:

• lubricating bearings, engines, and gearboxes,
• cooling and lubricating tools in surface finishing and metalworking,
• power transmission in hydraulic systems,
• heat transfer in process engineering plants, and
• insulation of transformers and capacitors in electrical engineering.

The main component of these operating fluids is base oil. To meet the different stresses in various applications, additives are blended with the base oils. These include corrosion inhibitors, defoamers, or additives that improve flow behavior at extreme temperatures. During use, additional substances such as moisture, wear particles, chips, or dust get into the fluids.

In addition, oil ages, which alters its chemical properties. When it can no longer meet performance requirements, it must be replaced. To recycle the fluid after an oil change, foreign substances created or retained in it must be separated from the base oil. The more components it contains, the more complex the separation process becomes. For this reason, U.S. environmental regulations also require used oil to be collected and handled separately by origin to ensure recycling whenever possible.

Collection groups for used oils

By keeping used oils separated, the type and quantity of contaminants are minimized. Four categories of used oil are defined for recycling purposes, each with specific waste codes. Mixing between categories is strictly prohibited.

• Category 1
  Covers mineral-oil-based and synthetic machine, gear, and lubricating oils, as well as mineral-oil-based hydraulic, insulating, and heat transfer oils that do not contain chlorine compounds.
• Category 2
  Contains halogen-free synthetic and mineral-oil-based machining fluids as well as synthetic hydraulic oils.
• Category 3
  Designated for used oils containing halogens or highly toxic PCB compounds.
• Category 4
  Includes readily biodegradable used oils, synthetic insulating and heat transfer oils, oils from oil/water separators, as well as heating oil and diesel fuel.

How does used oil recycling work?

Used oil recycling takes place in several sequential process steps. Depending on the origin of the oil, certain steps may be necessary to repeat multiple times until the required purity of the base oils is achieved.

Removing solid components

Coarse solids that are heavier than oil and therefore sink over time, are removed by sedimentation. Once the solids have settled, the liquid is pumped off for further processing. Suspended solids are captured using filters arranged in sequence with increasingly fine pore sizes.

The remaining sludge and spent filter material are conventionally disposed of and utilized for energy recovery.

Oil drying

Moisture is usually removed from recovered fluids by adsorption dryers. The liquid flows through columns where water is retained by a molecular sieve. When the sieve is saturated, it is regenerated by heating.

Distillation

In distillation columns, used oil undergoes multistage distillation. The column has a reboiler at the bottom and a condenser at the top. As vapor rises and condensate trickles down, lighter fractions accumulate in the vapor, while heavier fractions concentrate in the liquid. The separated fractions are continuously drawn off from the top and bottom of the column.

Refining

Refining means upgrading. Unwanted substances that remain in the base oil after distillation are removed or converted by various methods. One example is hydrotreating, in which substances are converted by adding hydrogen. Sulfur and nitrogen compounds can be transformed into gaseous substances (hydrogen sulfide, ammonia) that escape from the liquid and are collected separately.

Further processing of base oils

Used oil recycling returns base oils—originally derived from petroleum—back into the economic cycle. By incorporating additives, lubricants for engines and transmissions, cooling fluids for metalworking, and other products are manufactured. Eventually, they once again become candidates for sustainable oil recycling.

Green chemistry in used oil recycling

Used oil recycling has advanced technologically since it became a central focus of waste management under circular economy laws and EPA waste regulations. When optimizing processes for energy efficiency and material recovery, the basic principles of green chemistry play a crucial role. For detailed information on green chemistry, see our article Sustainable Chemistry.

Because the base oils already exist, recycling requires fewer process steps than producing oils from crude petroleum. This results in lower energy consumption and therefore lower CO2 emissions.

Used oil recycling at Kluthe

Products derived from used oil recycling are components of many substances in Kluthe’s product portfolio. for example, our company, , offers non-water-miscible cooling fluids from the HAKUFORM S series, formulated using Hybase oil as the base. Hybase oil is produced from recycled oil using advanced technology.

Kluthe also pursues an environmentally responsible waste management concept. The company takes back spent products from customers and recycles them for reuse. Customers thus improve their waste footprint and, if desired, receive reprocessed materials back in the form of regenerated products.

Der Beitrag How sustainable is used oil recycling? erschien zuerst auf Kluthe Magazine.

Targets for Active Substances in Biocides

Forms of Target Organisms

The appropriate strategy for using biocides is based on the forms in which the respective target organisms appear. In disinfectants, these are pathogens. Other biocides act against algae, mold, or rot bacteria. Controlling insects (e.g., mosquitoes, moths, lice, bedbugs) with biocidal products requires careful consideration to protect beneficial insects. Special caution is also required when active substances are intended to control vertebrates (e.g., rats, mice, pigeons).

Mode of Action of Biocides

Living organisms differ from non-living matter through their metabolism. Anything that takes in nutrients, converts them into its own bodily substances, and excretes waste products is alive. These substances enable growth and reproduction. This process ends when a biocide destroys  the structure of the organism or blocks its metabolic processes.

Many microorganisms form dormant stages known as spores, which can survive for prolonged periods without nutrients. When environmental conditions become favorable, metabolism resumes and the spores awaken. Only extreme external influences—such as very high temperatures, aggressive chemicals, or strong mechanical forces—can destroy these dormant forms.

Viruses are a special case. They differ from living organisms because they have no metabolism of their own, and from inanimate matter because they can replicate inside host cells. The host defends itself by producing antibodies until it eliminates the viruses or its metabolism fails. Biocides intercept viruses on their way from one host to another.

Requirements for Biocides

Two requirements are central when using biocides: first, they must be effective. Second, their effect must be achieved without  imposing undue burdens for humans, animals, and the environment. Chemicals may only be placed on the market as biocidal products if it has been demonstrated that they meet both requirements. With the Biocidal Products Regulation (EU No. 528/2012), a demanding regulatory framework was established in Europe. In the United States, the Environmental Protection Agency (EPA) regulates similar products under FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act).

Biocidal Active Substances and Biocidal Products

The Regulation (EU No. 528/2012) distinguishes between biocidal active substances and biocidal products. Biocidal active substances are chemicals that kill harmful organisms. Biocidal products are substances placed on the market. These may be pure active substances or mixtures containing such substances.

Determining Properties and Characteristics

To evaluate a biocide, the  responsible authority requires precise information about the properties and characteristics of the chemical, the test procedures used, and the intended method of application. In particular, the following must be clarified:

• its efficacy against target organisms
• its effects on humans and animals
• its behavior in the environment
• required occupational and environmental protection measures

Classification of Biocidal Products into Main Groups

The necessary and permitted characteristics of biocides depend on their intended use. The classification into biocidal product types provides orientation. The system consists of four main groups:

• Main group 1: disinfectants for combating pathogens
• Main group 2: preservatives for materials
• Main group 3: pest control products to prevent uncontrolled spread of certain species
• Main group 4: other biocidal products, such as those used to protect structures in water or biological preparations

Areas of Application for Disinfectants

Disinfectants contribute to hygiene in a wide variety of application areas. Accordingly, the properties required of the chemicals and the associated risks vary. For this reason, biocides in main group 1 are assigned to specific product types.

• Product type 1 includes products intended for human hygiene. As they come into direct contact with the skin, harmful side effects must be ruled out. These products are subject not only to the provisions of the Biocidal Products Regulation, but also to pharmaceutical and medical device regulations. Hand disinfectants account for a large share of this product type.

• Product type 2 includes disinfectants and algaecides for treating surfaces, materials, and equipment. These chemicals are not intended for direct use on humans or animals nor for surfaces in contact with food or feed. They are used, for example, to disinfect swimming pool water, the air in air-conditioning systems, and walls and floors. Products for disinfecting chemical toilets, wastewater, or hospital waste also belong to this type.
• Product type 3 is used in the veterinary sector. These products disinfect the skin or mucous membranes of animals, as well as surfaces and materials used to house or transport animals.
• Biocides used in the food and feed sector to disinfect equipment, installations, and surfaces belong to product type 4. This also includes disinfectants for drinking water.

Use of Disinfectants

The effect of disinfectants depends on the concentration of active substances and on the contact time. These two factors determine how much of an active substance a harmful organism absorbs. A specific amount—determined by testing—is required to reliably kill it. Additional tests determine the risks to humans, animals, and the environment that are associated with using these chemicals.

The results form the basis for the instructions for use. Users can obtain information about methods, frequency, and dosage, as well as protective measures for humans, animals, and the environment.

Hand disinfectants, for example, must be thoroughly applied to all areas of the skin and allowed to act for at least 30 seconds. The active substance in these products is usually alcohol, which is classified as a flammable liquid and can form an explosive atmosphere when mixed with air. Therefore, ignition sources must be avoided when handling hand disinfectants.

Der Beitrag What Are Biocides and What Role Do They Play in Disinfectants? erschien zuerst auf Kluthe Magazine.